Wireless charging systems are capable of transferring power in free space, e.g., via a wireless magnetic field, to be used for charging electric vehicles. However, the wireless magnetic field may induce eddy currents in any metallic object located within a predetermined space near the wireless charging system. Such eddy currents cause the metallic object to heat up and may damage components of the wireless charging system. Sensor systems which include a plurality of sense coils may be utilized to determine the presence of such metallic objects for accordingly reducing or discontinuing wireless power transfer. However, conventional square or rectangular shaped sense coils suffer from reduced sensitivity when such metallic objects are located substantially at a center of one of these sense coils and the dimensions of the sense coils are considerably larger than the dimensions of the metallic objects. Moreover, where the sense coils are located over the magnetics of a transmitter of the wireless charging system, the wireless magnetic field generated by the transmitter may cause undesirable interference with the sense coils. As such, sense coil geometries with improved sensitivity for metallic object detection in a predetermined space are desirable.